Bi-directional Forwarding Detection (BFD) is the technology responsible to detect the link down in the milliseconds region. It is important to be used specially in Datacenter, where any link failure should be detected very fast so the network can converge. This of course requires a proper redundant network otherwise there would be not much of convergence going on.
The configurations are very simple.
ip address 184.108.40.206 255.255.255.0
bfd interval 50 min_rx 50 multiplier 3
router eigrp 100
bfd interface Ethernet0/1
First, create the instance of BFD in the interface, then associate that instance within the router process with the interface.
Hope this was informative.